A synthetic skin microbial community (SkinCom) enables reproducible investigations of the human skin microbiome

Existing models of the human skin have aided our understanding of skin health and disease. However, they currently lack a microbial component, despite microbes' demonstrated connections to various skin diseases. Here we present a robust, standardized model of the skin microbial community (SkinCom) to support complex in vitro and in vivo investigations. Our methods lead to an accurate, reproducible, and diverse community formation of aerobic and anaerobic bacteria. Subsequent testing of SkinCom on the dorsal skin of mice allowed for DNA and RNA recovery from both the applied SkinCom and from dorsal skin, highlighting its practicality for in vivo studies and -omics analyses. Furthermore, our results indicate that 65.6% of the responses to common cosmetic chemicals in vitro were recapitulated in a human trial. Therefore, SkinCom represents a valuable, standardized tool for investigating microbe-metabolite interactions and facilitates the experimental design of in vivo studies targeting host-microbe relationships.